Polish AFOL Paul “Sarial” Kmiec (who built this neat robot arm) has created a Lego gear ratio calculator that lets you create complicated sets of gears and gives you speed, torque and ratios. Another tool lets you position two axles, then tells you what gears will work with that configuration. Lastly, you can choose which motor you’re using and it will compute output speed and torque for that gearset. Nice. [Via The NXTStep]